Gas turbine plant



March 23:, 1951 R STRUB 2,544,941

GAS TURBINE PLANT Filed May 2, 1944 I g 7 g l x h- 4 39 I13 INVENTOR:RENE STRUB ATTO EY Patented Mar. 13, 1951 UNITED STATES PATENT OFFICEGAS TURBINE PLANT Ren Strub, La Chaux-de-Fonds, Switzerland, assignor toSulzer Freres, Societe Anonyme, Winterthur, Switzerland Application May2, 1944, Serial No. 533,676

bine to the turbo-compressor a heat-exchanger may be provided throughwhich heat is supplied to the expanded fresh air. It is expedient forthe waste heat from the plant, for instance that contained in the heatedcooling-water, to be supplied to this heat-exchanger. It is preferableto regulate the passage of heating medium through the heat-exchanger inaccordance with the air temperature at the entrance to theturbocompressor in such a way that the air temperature is adjusted toaconstant level. The passage of heating medium can be interrupted assoon as the air temperature at the entrance to the turbo-compressorexceeds a certain fixed figure. The passage of cooling-medium throughthe cooler can be so regulated that the temperature of thecooling-medium remains at an approximately constant level.

One exemplification of the invention is explained in more detail belowwith the aid of the drawing.

The working-medium compressed by the lowpressure compressor I passesthrough the intermediate cooler 2 into the high-pressure cornpressor 3and then, after having been brought up to the maximum working pressure,is preheated in the tubes of the heat-exchanger 4. At the point 20 inthe outlet pipe from the heatexchanger the working medium is divided. Apart of it passes through pipe 2| into the heater 5' where it fiows overthe heat-exchange tubes and is brought up to the maximum workingtemperature.

The compressed and heated working medium then passes into the turbine 6,expands there and flows into the space surrounding the tubes of theheat-exchanger 4, where it gives up part of its residual heat to theworking medium coming from the compressor 3. A further part of theresidual heat is led off by a coolingmedium in the cooler 1, whereuponthe working medium again flows to the low-pressure compressor l andrecommences the circuit.

burner of the gas heater 5 as combustion air.

The combustion gases flow through the heatexchange tubes and then passto the turbine 8 from which they can be led 01f after expansion tofurther points of consumption not shown in the drawing, for instance toheat-exchangers, or to atmosphere.

,The turbo-compressor I l continually supplies air from the atmosphereto the open circuit in the plant to replace the quantity withdrawn. Thismake-up quantity is introduced into the heat-exchanger 4 at a point atwhich the working medium flowing back from the turbine 6 is atapproximately the same temperature as the make-up quantity.

The turbine 6 operated by the flow of work- 7 ing medium in the circuitdrives the compressors The other part of the working medium after I, 3and H, while the turbine 8 operated by the quantity withdrawn producesthe useful output given up to the outside. This useful output turbine,for instance, drives the ship's propeller 24 through the useful outputshaft 25 and the gear 23. The useful output is adjusted to be greater orless by the raising or lowering of the sequence of pressures of theworking medium flowing in the circuit.

A turbine 9 with an adjustable distributor I0 is provided before theturbo-compressor I l which continuously supplies the fresh air. Theoutput of this turbine is transmitted to the useful output shaft 25. Theair from atmosphere passes through the distributor II] to the blades ofthe turbine rotor. Each blade of the distributor I0 is mounted on ashaft placed at right angles to its profile. All the blades can beadjusted in common about the shaft, so that the crosssection of flowthrough the distributor is increased or reduced and at the same time theinflow angle of the air is made steeper or flatter. After expansion inthe turbine to a pressure below atmospheric the air passes through thepipe 26 to the turbo-compressor II.

The air is compressed by the turbo-compressor H to a higher or a lowerpressure according to the degree of expansion in the auxiliary turbine.In this way the sequence of pressures in the working medium circuit isalso adjusted to be higher or lower and the useful output is thusincreased or diminished. If the distributor I!) is adjusted for a largercross-section and a steeper inflow angle, then a higher sequence ofpressures results and consequently a greater output is obtained from theplant than when the distributor is adjusted for a smaller cross-sectionofflow and a flatter inflow angle.

In the pipe 26 a heat-exchanger I2 is arranged through which heat issupplied to the fresh air expanded in the auxiliary turbine. Thecoolingmedium heated in the cooler I flows through the tubes of theheat-exchanger I2 and gives off part of its heat to the expanded air. Inthis way the danger of ice formation in the compressor l l, is obviated.The fresh air can be supplied to the compressor at a temperature atwhich the moisture in the air is no longer precipitated in the form ofneedles of ice on the walls of the. .the adjustable blading IQ of theturbine 9 is pipes and the compressor blades.

In the supply pipe 2? of the heat-exchanger 12 a regulating member M isprovided. Further, a by-pass pipe 28 with a regulating member lv isconnected to the pipe 21. Both regulating members l4 and I5 arecontrolled by a. thermostat [3, which in its turn is inffuenced by the"fresh air heated in the heat-exchanger IE2. B'yfi] means of thisregulating device the temperature of: the fresh air is maintained atsuch a level:

that no ice formation can take place and further no undesirable increasein the work of compres sion in compressor H arises. 1 V When the outputof the whole plant is high,v only a slight expansion of. the air in theturbine 9, if any, takes place, so that the air temperature remainsabove freezing point when the temperature of the surrounding air isnormal. In this case the heating of the; heat-exchanger would only beharmful to the running of the whole plant because of the increase in thework done by the compressor. The passage of water through theheat-exchanger i2 is then completely interrupted. is closed while theregulating member W in the by-pass pipe is' open.

When the output decreases, increased expansion of the fresh air iscaused by the adjustment of the distributor if] of the turbine 9. Asexpansion increases, the cooling of the fresh. air is intensified. Ifthe air temperature approaches freezing point, the regulating member Mis opened by the thermostat i3 and the heating medium is freed to flowthrough the tubes of the heat-exchanger l2. The control by thethermostat l3 can be so adjusted that, for instance, the supply ofheat-isinterrupted at air temperatures above 4 C.,

while at temperatures below 4 C. heating medium is supplied in suchquantities that the air ESE l perature only falls very slightly below 4C. In, this way the temperature can be maintained-in the neighbourhoodof 4* 0. approximately.

In the cooling-medium supply pipe '29 ofthe; cooler l a regulatingmember is is provided which is influenced by the thermostat ea in thepipe 21. The influencing of the regulating member Hi is effected in sucha way that the outlet temperature of the cooling-medium from the coolerremainsapproximat-ely constant. When the load on the plant is slight,this regulating member is nearer to its closed position in accordancewith the decreased heat abstraction. in the cooler 1', while when theload is greater, the member. is nearer to its open position. The end isthus attained. that, when the load on the plant is. slight, thedifierence of temperature between the heating medium and the air to beheated in the heat-exchanger i2 is sufficient to enable the. quantity ofheat particularly required to be supplied to the air.

To the pipe 22. leading from the turbine 9 to the turbo-compressor H isconnected a supply pipe 3| with a closing member -1, through which,

The regulating member; hi

25 compressor,.an air heater disposed 4 when the load on the plant isgreat, air can be introduced from atmosphere direct into the pipe 25,the turbine 9 being by-passed. In this way any throttling of the airsupplied to the turbocompressor H is avoided.

The invention offers the advantage that the balance of power providedand consumed by the turbo-set I, 3, 6, H can. he maintainedindependently of the load on the whole plant. The extra output whicharises from the regulation without loss of the turbo-compressor H bymeans of transmitted direct to the useful output shaft 25.

The transmission of the output of the turbine 9 to the useful outputshaft may in principle be effected equally well by electric, magnetic,hydraulic or similar means. The heating of the 'heat-exchanger'l2 mayalso be done by means ofexhaust gases from the plant or thecoolingmedium of another cooler, for instance the intermediate cooler 2.The heat might .alsobe transmitted direct from the coolers to the heatexchanger l2 without the use of a heatecarrying' medium. The heatedworking medium would then flow directly through the heat-exch'an'ger.'Iclaim: 1. A gas turbine, plant comprising, in combinai tion, anauxiliary operating circuit includin an auxiliary turbine, a maincompressor driven. by said turbine and receiving operating gas 8X7.hausted therefrom for compression, a gas heater for heating the gascompressed in said com-1 prssor and supplying heated and compressedgasto-said turbine for operating same, andi an aux-Q iliary aircompressorconnected to and driven by said turbine and having air intakemeans, and supplying compressed air to said auxiliary cir'e, cult aheador said heater; a power shaft, amain gas turbine receiving operating gasfrom said heater and connected to and driving said power shaft, and anatmospheric air pressure operated turbine connected for air how to andexhausting into said air intake means and connected toand supplyingpower to said main shaft and having adjustable air intake means forcontrolling the flow of air from the atmosphere to said auxiliary.circuit and the power output of said plant. 'ff

2. A gas turbine plant as defined in claim 1, comprising an air heaterdisposed in said air in,- take means and heating the expanded air drawnfrom said air-operated turbine before it enters the auxiliary aircompressor.

3. A gas turbine plant as defined in clai'mll', comprising conduit meansfor conducting th jex haust from said auxiliary turbine to saidcompressor, an air heater disposed in. said ai'r intake means forheating the expanded air drawn from said atmospheric. air pressureturbine; beg fore it enters the auxiliary air compressor, and heattransfer means connected with said conduit means and with said airheater for transferring heat from the exhaust of the auxiliary turbineto the air exhausted from the atmospheric airpres sure turbine. 4. A:gas turbine plant as defined in claim 3', said heat transfer meanscomprising a conduit having a heat receiving portion disposed in saidconduit means. and a heat dispensing portion. dis posedin said airheater and a heat carrying fluid circulating from the first portion tothe second portion of said conduit. 7

5. A gas turbine plant as defined in claim' l comprising conduit meansfor conducting the-exhaust from said auxiliary turbine to said mainintake means for heating the expanded air drawn from said atmosphericair pressure turbine before it enters the auxiliary air compressor, aconduit for a heat carrying fluid, having a heat receiving portiondisposed in said conduit means and a heat dispensing portion disposed insaid air heater for transferring heat by said fluid from the exhaust ofthe auxiliary turbine to the air exhausted from the atmospheric airpressure turbine, and temperature responsive control means connectedwith said conduit and controlling the flow of heat carrying fluidtherethrough.

6. A gas turbine plant as defined in claim 1, comprising conduit meansfor conducting the exhaust from said auxiliary turbine to said maincompressor, an air heater disposed in said air intake means for heatingthe expanded air drawn from said atmospheric air pressure turbine beforeit enters the auxiliary air compressor, a conduit for a heat carryingfluid, having ,a heat receiving portion disposed in said conduit meansand a heat dispensing portion disposed in said air heater fortransferring heat by said fluid from the exhaust of the auxiliaryturbine to the air exhausted from the atmospheric air pressure turbine,temperature responsive means connected with said air intake meansbetween said air heater and said auxiliary air compressor, and controlmeans connected with said temperature responsive means and with saidconduit and controlling the flow of heat carrying fluid through theportion thereof disposed in said air heater in dependence on thetemperature of the air entering the auxiliary compressor.

7. In a gas turbine plant, the combination of a turbo-compressorsupplying the compressed air needed by said plant and having air intakemeans, a main power shaft, a main turbine connected with and operatingsaid shaft, an atmospheric air pressure operated turbine disposed forair flow in said air intake means and being connected with andcontributing power to said shaft, adjustable air intake guide vanesconnected with said air operated turbine and controlling the flow of airfrom the atmosphere to and the power output of said plant, a heatexchanger connected to and receiving heat from gas exhausted by theturbine of said turbo-compressor and transferring it to a heat carriermedium, flow control means connected with said heat exchanger andcontrolling the flow of said medium therethrough and being responsive tothe temperature of said medium as it leaves said heat exchanger, and anair heater receiving heat from said medium and being disposed in saidair intake means and heating the expanded air drawn from saidairoperated turbine before it enters the compressor of saidturbo-compressor.

RENE STRUB.

REFERENCES CITED The fo lowing references are of record in the file ofthis patent:

UNITED STATES PATENTS

